Penstemonspp.: The penstemons (or
beardtongues) are among the most beautiful of our wildflowers. Their five
petaled flowers have two paired stamens. There is always a fifth sterile
stamen (a staminode) without an anther at its tip. It may be
hairy and partially occlude the floral throat of the flower, hence the common
name beard-tongue. The flowers are born in whorls, known as
verticillasters  (seen clearly in the illustrations). Most
are blue, purple, or lavender, but pink, white and even red species also
occur. Because there are many similar species, they may be difficult to identify.
The name penstemon was derived from the Greek pente meaning
five for five stamens. There are over 250 species of penstemon;
most are native to the American west; in the Northwest alone, there are 80
or so species. Some of the species that grow in our mountains are shown
here.Although listed under Scrophulariaceae, taxonomists
now believe that they should be in the plantain family
(Plantaginaceae).

Shrubby penstemon, Penstemon
fruticosus (Pursh) Greene (left, right)
The shrubby penstemon is an attractive, and common species that grows from
midelevations into the subalpine zone. Its stems are woody, and its
leathery leaves are evergreen. When mature, the plants form shrubs that may
grow to be quite large (left). Showy, light-purple flowers are up to two
inches long. Several varieties are recognized, identified mostly by the form
of the leaves. Ours, illustrated here, with lanceolate, smooth-edged leaves
is var. fruticosus, the most common variety. Lewis and Clark found
the shrubby penstemon while on the Lolo Trail (June 15, 1806).

Mountain penstemon, Penstemon
montanusGreene var.
montanus(left, right) is another woody species
It is usually seen growing near treeline or higher. Like the shrubby penstemon,
it forms well demarcated shrubby clumps. Large violet flowers, woody stems,
toothed leaves, and the high elevation at which it grows, serve to identify
the plant. A related variety, Penstemon montanus var.
idahoensis (D. D. Keck) Cronquist, with mostly smooth-edged leaves,
grows only in Idaho.

Taperleaf penstemon, Penstemon
attenuatus Douglas
ex Lindl. (left; also sulphur penstemon for
the color of one of its several varieties) is common in our mountains, often
present in large patches. It is characterized by its discrete, crowded flower
clusters (verticillasters) and is sometimes confused with
Penstemon rydbergii A. Nelson, a similar plant
with well defined flower clusters that grows at lower elevations.

Hot-rock penstemon, Penstemon
deustus Douglas ex Lindl.
(right) grows mostly on cliffs and other rocky surfaces.
That growth preference, as well as its white flowers and shallowly serrated
leaves, serves to identify the plant.

Payette Penstemon, Penstemon
payettensis Nelson & J. F.
MacBride (left), first collected in the Payette National
Forest, is a central Idaho plant extending to western Oregon. It favors open
sagebrush slopes, and grows high in the mountains. The plant stands out because
it is tall, to two feet or more, and has large, deep blue, showy
flowers. Identification of the various penstemons can be difficult as it
is based both on the morphology of the plant, and on the configuration of
the anthers and their four pollen sacs--visible in this illustration, although
best seen with magnification and dissection of the flowers.

Dark blue penstemon, Penstemon
cyaneus Pennell (right) is a
similar, colorful, large-flowered plant that grows only in Idaho, Montana
and Wyoming. A tendency for its flowers to be borne along one side of the
stem distinguishes it from the Payette penstemon

Pale yellow penstemon,
Penstemon confertus, Douglas ex Lindl.
(left) is found in the northern half of Idaho. Its pale yellowish-white
(ochroleucous) flowers distinguish the plant, as do purple anther
sacs and bearded stamen. The name confertus means
crowded, presumably for the flower clusters, although they are
no more crowded than those of many other species.

Small-flowered penstemon, Penstemon
procerusDouglas ex Graham
(right) is the most common of Idahos penstemons.
It has small, narrow-tubed, densely arrayed flowers with lips that often
close the mouth of the flower. The plants are common throughout the West,
from foothills to above tree-line.

Pink Penstemon,
Penstemon confertus x
procerus? The many species of penstemon, their
variability, and a tendency for species to cross-breed, gives credence to
the belief that the genus Penstemon is one that is actively evolving.
The pink penstemon shown here is an example. It appears
to be a hybrid between the two species shown above, Penstemon confertus
and Penstemon procerus (see Strickler, D.: Northwest
Penstemons)

Wilcoxs penstemon, Penstemon
wilcoxiiRydb. (left) grows in the northern half of Idaho,
spilling over into neighboring states. The plants are tall, with finely serrated,
large stem leaves, and a series of long paired stemlets that help to identify
the plant. These bear clusters (panicles) of moderately large,
blue flowers. The plant was collected by Meriwether Lewis near Kamiah, Idaho,
in 1806.

Two penstemons with similar, large, light purple flowers are:

Fuzzy-tongue penstemon, Penstemon
eriantherus Pursh (left) bears a few large,
wide, light purple flowers with more-or-less prominent guide-lines
within the throat. While eriantherus means hairy-anther,
the degree of hairiness, and the prominence of the guide-lines varies
considerably among the five recognized varieties. The Idaho variety, var.
redactus Pennell & D. D. Keck, is a low plant with a rather sparsely
bearded yellow stamen.

Twinleaf penstemon, Penstemon
diphyllusRydb. (right). The twin-leaved (diphyllus)
penstemon is characterized by large pale-purple flowers whose upper lips
are split for more than half their length, and by paired, toothed leaves
ranged along the stem. A mountain plant, it grows in southern Idaho, as well
as in Washington and Montana.

Globe penstemon, Penstemon
globosus(Piper) Pennell &
Keck (left). The globe penstemon is found in central and
northern Idaho and in adjacent parts of Oregon. It is characterized by its
opposing broad-based, stemless, lanceolate leaves. The species name,
globosa, means "spherical" apparently referring to the obvious spherical
shape of the top cluster of flowers. (The white flowers in the images
are yarrow, Achillea millefolium.)

Tweedys snowlover, Chionophila tweedyi
(Canby & Rose) L.F. Hend. (left, right) appears
soon after the snowmelt. Half a dozen or so lavender-tinged flowers, their
lips turned up at the end, bloom on one side of a stem that arises from a
basal rosette of small oval leaves. The plant is related to the penstemons,
and was formerly classified as Penstemon tweedyi. Although occasionally
seen lower, it mostly grows high in the mountains of Idaho and neighboring
Montana. The name honors Frank Tweedy (1854-1937), a topographical engineer
with the U.S. Geological Survey. Chionophila is from the Greek xioni
meaning snow and filos for friend. The inelegant
name toothbrush flower has also been applied to the plant.